ESTABLISHMENT OF A ZEBRAFISH XENOGRAFT ASSAY TO ANALYZE GLIOBLASTOMA CELLS-MICROENVIRONMENT INTERACTIONS AND THERAPEUTIC RESISTANCE

Zebrafish are emerging as powerful in vivo models in cancer research due to the transparency of the embryos, their rapid development, and in vivo drug screening. These advantages enable real-time visualization of tumor cell behavior and provide cost-effective and flexible alternative to traditional mammalian models. Zebrafish xenograft systems have gained increasing attention for studying tumor-microenvironment interactions in Glioblastoma (GBM), an aggressive primary brain tumor characterized by extensive invasion into surrounding brain tissue and limited response to current strategies. Here, we aimed to utilize a zebrafish xenograft model to analyze GBM cell interactions with the brain microenvironment as well as drug resistance behavior using our paired GBM cell line, U87MG and its Temozolomide-resistant derivative, U87MG-TR. Accordingly, the in vitro behavior of the U87MG and U87MG-TR were characterized using cell viability assays and morphological analyses. In parallel, zebrafish injection protocols were optimized in transgenic lines. Preliminary results revealed that both the U87MG and U87MG-TR cells exhibit adherent, epithelial-like characteristics, and requiring strong cell–cell adhesion for optimal survival. U87MG-TR cells display significantly higher IC50 to Temozolomide, which is a DNA alkylating agent and the first-line chemotherapeutic for GBM. Our current efforts are focused on analyzing the transplantation capacity of both the U87MG and U87MG-TR cells, which are engineered to stably express GFP or mCherry using lentiviral transduction. The in vivo behavior of these cells will be monitored in zebrafish larvae and analysis will be performed with confocal microscopy.